1. Field of the Invention
The present invention relates to a method and apparatus for sharing a frequency in an environment where an incumbent system exists.
2. Description of the Related Art
Due to the development in radio communication technologies and the introduction of new radio communication services, there has been a desire to more effectively use a finite frequency resource. To enhance a frequency utilization efficiency, a spectrum efficiency optimization scheme through a performance optimization of a radio communication system and a scheme of minimizing interference with another radio communication system, and the like have been used. The performance optimization may be, for example, a multiple access scheme, an encoding technology, a modulation efficiency, an information compression technology, and the like.
In addition to the above schemes, a frequency sharing method is proposed to enhance a frequency utilization efficiency in a currently using frequency band such as a television (TV) band.